1. Field of the Invention
This disclosure relates to a semiconductor device, and more particularly, to a voltage boosting circuit that generates a boosting voltage that is higher than the external supply voltage and a method of generating the boosting voltage.
2. Description of the Related Art
Semiconductor memory devices use a boosting voltage that is higher than the external supply voltage to access memory cells. In general, a pumping circuit is used to boost a supply voltage power level to the boosted voltage power level.
The pumping circuit used in the semiconductor memory devices boosts the voltage at an internal node and outputs the boosted voltage via a driver transistor. Hence, high voltage stress is imposed on the driver transistor, and thus, the driver transistor may undergo deterioration. The deterioration intensifies as the supply voltage power level increases.
Recently, a decrease in the operating voltage of the pumping circuit, i.e., the external supply voltage, has resulted in an increase in the number of boosting stages of the pumping circuit allowing for high pumping efficiency. As a result, the problems related to high voltage stress become even more serious than before.
Embodiments of the invention address these and other disadvantages of the art.